CFRP Electronics Housing for a Satellite (ESA 2005)

The laminated composite lay-up design typically involves trade-offs between material selection, thickness of the layer, orientation of the layers, and the stacking sequence. Finding the right structural concept early in the design process leaves resources for the detailed design. Many structural members made of laminated composite materials have the form of thin walled cylindrical shells that are prone to buckling. Thus it is desirable to find structural designs that satisfy global requirements for structural stability early in the design phases. In this work, thin-walled cylindrical composite shells under different loading conditions have been studied for structural stability. The simulation is performed with a shell facet model implemented in the ESAComp software. Preliminary design tools for structural stability of thin-walled cylindrical composite shells are demonstrated and discussed.

Layered composites have proven essential for the successful design of high-performance space structures. The aviation industry are increasingly using more and more layered composites within commercial aircraft, replacing traditional aluminum designs, to achieve weight savings. When optimizing layered composite structures it is desirable to find design solutions that satisfy global requirements early in the design phases. Particularly because of the number of design variables associated with composite layups once models become more detailed are complex:

Fast tools such as the ESAComp module for bonded joints can be very efficient in the preliminary design of various joint configurations. In this example we consider a tip loaded wing of a small aircraft or wind turbine blade. The wing spar carries a constant in-plane shear (Nxy), which needs to be transferred from the joint laminates to the shear web.

Composite material systems have relatively large variation in their measured properties. A typical approach in engineering problems is deterministic, however. Material stiffness and strength, for example, are described with single values in linear-elastic analyses. Physical dimensions of the material, structural and environmental conditions in the laminate or uncertainties in material properties, for instance, require that several discrete definitions are needed for the material specification.

This paper describes how a carbon fiber reinforced plastic body of a future city car was optimized to minimize weight. The frame includes numerous parts, some of which have a simple constant laminate structure and some are more complex having additional local reinforcements. The body must meet the different stiffness and load carrying constraints set by the various load cases.

For many years, layered composites have proven essential for the successful design of high-performance space structures, such as launchers or satellites. A generic cylindrical composite structure for a launcher application was optimized with respect to objectives and constraints typical for space applications. The studies included the structural stability, laminate load response and failure analyses. Several types of cylinders (with and without stiffeners) were considered and optimized using different lay-up parameterizations. Results for the best designs are presented and discussed.

This paper describes the method for transverse shear analysis to be applied in the composites design program ESAComp. The correlation of the method to the formulations used in the commercial finite element programs is presented and the results from the selected method are compared to the exact elasticity results. The results show good agreement with the exact solutions for cross-ply and unsymmetric angle-ply laminates. Symmetric angle-ply laminates create bending twisting coupling that the theory cannot accurately model.

This paper presents a newly developed analysis and design module for adhesive bonded joints implemented in ESAComp, software for analysis and design of composite laminates and laminated structures.

In the framework of a development project promoted by the European Space Agency (ESA/ESTEC), Airbus Defence & Space (EADS CASA Espacio, ECE) has designed, manufactured and tested a technology demonstrator representative of the payload adaptor (PLA) of VEGA Launcher, by using an anisogrid concept, called anisogrid payload adaptor (APA).